Streaming fusion exists, and can easily be implemented in C++, that's what authors of this library should have done. C++ ranges library (proposition for C++17)

Streaming fusion exists, and can easily be implemented in C++, that's what authors of this library should have done. C++ ranges library (proposition for C++17) will make this kind of thing possible without any overhead. Realistically, STL interface for sequences is pretty bad and barely composable. This is not a problem with "functional style", it's a problem with library design. writing map (+2) (map (+1) (map (+3) xs)) will be just a single pass over a list in Haskell, with 3 function applications (maybe 1 if that is optimized to (+6)).